Wire-drawing die.



F. KRAUSE.

WIRE DRAWING DIE.

APPLICATION FILED JAN. 3, 1912.

1,056,555. Patented Mar. 18,1913.

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FREDERICK KRAUSE, or JERSEY CITY, NEW messy.

, WIRE-DRAWING DIE.

Specification of Letters Patent.

Patented Mar. 18, 1913.

Application filed January 3, 1912. Serial Not 669,481.

wire drawing dies and pertains particularlyto metal set wire dies.

It is the special object of my invention to produce metal set wire dies having a diamond with bore whose protective metallic mantle or ring has a very low coeflicient of expansion and contraction. Heretofore such wire dies were protected against injury to the bored diamond by casting around same a protective mantle or ring of steel, which, however, possessed serious deficiencies. At the present time the metal set diamond wire drawing dies are of increased importance, as large numbers of same are used now for drawing the exceedingly fine wires for metallic filaments for incandescent electric lamps, which filaments consist of rather refractory and hard metals, as tungsten, osmium, tantalum, etc. Such exceedingly fine wires for metallic filaments for incandescent electric lamps may also be drawn Whil'e'the relatively thick wire to be drawn is in. a hot, or even glowing, condition. Under these circumstances the metal set wire dies failed to work satisfactorily because the protective steel mantle expands so much that the bored diamond evidently had not the protection against injury which was expecte'd from former experiences with such dies when used for drawing wires at ordinary temperature. Practical observations and tests have proved that at higher temperaturesthe protective steel envelop of the bored diamond expands considerably more than the diamond itself. Accordingly with increasing temperatures during the process of drawing the wire, the efi'ectiveness of the protective steel envelop decreases and may even cease entirely.

It is the special object of the present invention to overcome the described deficiencies and' produce a protective metallic envelop or mantle which has a very low coefiicient of expansion and contraction. Such envelop is preferably made of nickel or a nickel alloy, the components of which are so selected that the alloy has the property of expanding under heat about twelve times less than steel. Metallic envelops having such a low coefficient of expansion afford fullest protection against any fracture of the diamond around its bore, even if hard wires are drawn at higher temperatures. It is evident that suchdies are perfectly protected when wires are drawn thereby at ordinary temperature.

The invention-is illustrated in the accompanying drawing in which:

Figure 1 represents in top planview the protective setting with bored precious stone, and Fig. 2 is a vertical cross section of same.

Similar letters of reference denote like parts in both figures.

In the drawing A represents the precious stone or diamond, B is the protective setting or metallic envelop, C is the top portion of the opening in the setting, C the bottom portion of-same and D represents the bore in the precious'stone or diamond.

The alloy used for the novel mantle, envelop, or ring is a nickel-steel alloy. A

nickel-steel alloy answering the purposes of this invention .consists of about of nickel and of about 3 of steel. Such nickel steel alloy, containing a high percentage of nickel presents the additional advantage that it possesses a considerably higher resistance against acids used during the proc ess of drawing wires than a steel envelop. The acids corrode steel and even dissolve it relatively easily, while the nickel-steel alloy is practically not attacked. The nickelalloyenveloplmay be east tightly around the stoneand does not require a special protective surface covering'of brass, for instance, which is needed on steel mantles when wires are drawn at ordinary temperature while submerging the die under water. The steel mantle certainly oxidizes quickly under water, while the nickel alloy mantle is not affected thereby.

I claim as my invention p 1. A protective setting for wire drawing dies with bored precious stones consisting of a metallic mantle or ring having a very low coeflicient of expansion in comparison with the bored precious, stone employed.

2. A protective setting for wire drawing dies with bored precious stones consisting of a nickel-steel mantle or rin having a very low coefiicient of expansion in comparison with the bored precious stone employed.

3. A protective setting for wire drawing dies with bored diamond consisting of a. nickel-steel mantle. or ring cast around same and having a very low coefficient of expansion in comparison with the bored diamond so that exceedingly fine wires may be drawn from thicker wires while same are highly heated.

4. A wire drawing die consisting of a protective metallic setting and a bored precious stone, said protective setting having a Very low coefiicient of expansion in comparison with the bored precious stone incased therein.

5. A die for drawing fine wires consisting of a protective metallic setting of nickelsteel and a bored precious stone incased therein, said protective setting having a very low coeflicient of expansion in comparison with the bored precious stone.

6. A die for drawing fine wires consisting of a protective nickel-steel settin and a bored diamond incased therein, sai rotective setting having a very low coefiiclent of expansion in comparison wit-l1 the bored diamond so that exceedingly fine wires may be drawn from thicker wires when same are highly heated without injuring the boring of the diamond.

Signed at New York, N. Y., this 16th day of December 1911.

FREDERICK KRAUSE.

lVitnesses MARIE H. BRAUN, LUDWIG K. BoHM. 

